The lunch expansion is no surprise. Caribou executives have said the chain planned to expand its food offerings to keep revenue strong in the later part of the day— it's hard to sell customers muffins and egg sandwiches at lunchtime.

"Our customers stop in for their favorite beverages all day long, so offering food that can be enjoyed for breakfast as well as lunch or dinner was a natural next step for Caribou." Alfredo Martel, Caribou's senior vice president of marketing and product management, said in a statement.

The sandwiches cost from $3.50 to $4.25, depending on store location, Caribou said in a news release.